hw_breakpoint: Factor out __modify_user_hw_breakpoint() function

Moving out all the functionality without the events
disabling/enabling calls, because we want to call another
disabling/enabling functions in following change.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Hari Bathini <hbathini@linux.vnet.ibm.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Milind Chabbi <chabbi.milind@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Oleg Nesterov <onestero@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Link: http://lkml.kernel.org/r/20180312134548.31532-5-jolsa@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/kernel/events/hw_breakpoint.c b/kernel/events/hw_breakpoint.c
index 776948b..a556aba 100644 (file)
--- a/kernel/events/hw_breakpoint.c
+++ b/kernel/events/hw_breakpoint.c
@@ -456,6 +456,33 @@ register_user_hw_breakpoint(struct perf_event_attr *attr,
 }
 EXPORT_SYMBOL_GPL(register_user_hw_breakpoint);
 
+static int __modify_user_hw_breakpoint(struct perf_event *bp, struct perf_event_attr *attr)
+{
+       u64 old_addr = bp->attr.bp_addr;
+       u64 old_len  = bp->attr.bp_len;
+       int old_type = bp->attr.bp_type;
+       bool modify  = attr->bp_type != old_type;
+       int err = 0;
+
+       bp->attr.bp_addr = attr->bp_addr;
+       bp->attr.bp_type = attr->bp_type;
+       bp->attr.bp_len  = attr->bp_len;
+
+       err = validate_hw_breakpoint(bp);
+       if (!err && modify)
+               err = modify_bp_slot(bp, old_type);
+
+       if (err) {
+               bp->attr.bp_addr = old_addr;
+               bp->attr.bp_type = old_type;
+               bp->attr.bp_len  = old_len;
+               return err;
+       }
+
+       bp->attr.disabled = attr->disabled;
+       return 0;
+}
+
 /**
  * modify_user_hw_breakpoint - modify a user-space hardware breakpoint
  * @bp: the breakpoint structure to modify
@@ -465,11 +492,7 @@ EXPORT_SYMBOL_GPL(register_user_hw_breakpoint);
  */
 int modify_user_hw_breakpoint(struct perf_event *bp, struct perf_event_attr *attr)
 {
-       u64 old_addr = bp->attr.bp_addr;
-       u64 old_len = bp->attr.bp_len;
-       int old_type = bp->attr.bp_type;
-       bool modify = attr->bp_type != old_type;
-       int err = 0;
+       int err;
 
        /*
         * modify_user_hw_breakpoint can be invoked with IRQs disabled and hence it
@@ -482,18 +505,9 @@ int modify_user_hw_breakpoint(struct perf_event *bp, struct perf_event_attr *att
        else
                perf_event_disable(bp);
 
-       bp->attr.bp_addr = attr->bp_addr;
-       bp->attr.bp_type = attr->bp_type;
-       bp->attr.bp_len = attr->bp_len;
-
-       err = validate_hw_breakpoint(bp);
-       if (!err && modify)
-               err = modify_bp_slot(bp, old_type);
+       err = __modify_user_hw_breakpoint(bp, attr);
 
        if (err) {
-               bp->attr.bp_addr = old_addr;
-               bp->attr.bp_type = old_type;
-               bp->attr.bp_len = old_len;
                if (!bp->attr.disabled)
                        perf_event_enable(bp);
 
@@ -502,8 +516,6 @@ int modify_user_hw_breakpoint(struct perf_event *bp, struct perf_event_attr *att
 
        if (!attr->disabled)
                perf_event_enable(bp);
-
-       bp->attr.disabled = attr->disabled;
        return 0;
 }
 EXPORT_SYMBOL_GPL(modify_user_hw_breakpoint);